The present invention relates to hair styling compositions. More particularly, the present invention relates to aqueous hair styling compositions containing low, or 70 weight percent or less volatile organic compounds (VOC). The present invention also relates to a method of enhancing the performance of hair fixative resins by adding certain additives to hair styling compositions.
Hair styling compositions, such as hair sprays, styling gels, spray on gels, and mousses are used on hair to hold the hair in a particular shape or configuration. The hair styling compositions, when applied, form a thin film of hair fixative resin on the hair. This thin film of resin holds adjacent hairs together to retain a particular shape or configuration.
The hair styling compositions can be applied to the hair in several ways. For example, the hair styling composition may be applied by a spray using a propellant, such as in an aerosol hair styling product, or using a hand pump.
Hair styling compositions typically contain one or more volatile organic compounds (VOC). VOC contain at least one carbon atom and are typically used as solvents or propellants in hair styling compositions. VOC contribute to ground level air pollution in the presence of sunlight and air, and are volatile under ambient conditions. VOC include, for example, C.sub.1 to C.sub.12 straight or branched chain alcohols such as methanol, ethanol, propanol, isopropanol, or butanol; C.sub.1 to C.sub.12 straight or branched chain hydrocarbons such as methane, ethane, propane, isopropane, isobutane, pentane, isopentane, or butane; or ethers such as dimethyl ether, or dimethoxymethane.
Recent legislation in New York and California has mandated that the amount of VOC formulated into hair styling compositions that are sprayed, such as hairsprays, must not exceed 80 weight percent in the composition. By 1998, the amount of VOC in hair styling compositions that are sprayed must be reduced to 55 weight percent in California. Other states may enact similar legislation mandating the reduction of VOC in hair styling compositions that are sprayed. Present hair styling compositions which are sprayed typically have equal to or greater than 80 weight percent VOC. The most likely replacement for VOC is water.
The introduction of water into the hair styling composition can adversely affect the performance of the composition. For example, depending on the hair fixative resin and other additives in the composition, water can cause the composition, when sprayed, to form droplets or beads on the hair. These beads leave undesirable visible residue on the hair when dried, and can impart a raspy feel to the hair when combed. Water also has the disadvantage of increasing the drying time of the hair styling composition after it is applied to the hair when compared to hair styling compositions containing higher levels of VOC.
Water can also adversely affect the properties of the hair fixative resin. For example, if the hair fixative resin is water soluble, water can cause high composition viscosities (greater than 15 centipoise) leading to decreased sprayability of the hair styling composition and clogging of the spray nozzle. Water soluble hair fixative resins, when used in low VOC hair styling compositions, are also more likely to become tacky after being applied to the hair. The water soluble hair fixative resins may also have poor curl retention properties due to their inability to dry completely when applied to the hair in a low VOC hair styling composition.
These undesirable properties become particularly severe when the hair styling composition contains about 15 weight percent or more water. As a result, hair styling formulators have begun to redesign their hair styling compositions.
A particular problem in developing a low VOC hair styling composition is finding a suitable plasticizer for the hair fixative resin. The plasticizer gives the hair fixative resin flexibility so that the resin when applied to the hair forms a film, which feels smooth and does not crack or break when combed. The water in a low VOC hair styling composition can adversely affect the plasticizer. For example, the plasticizer in a low VOC hair styling composition, can increase the tackiness, decrease the curl retention, or increase the drying time of the hair fixative resin. The plasticizer may also just be completely ineffective in plasticizing the resin in the presence of water.
Another problem in low VOC hair styling compositions is that the hair fixative resin, prior to being added to the hair styling composition, and the hair styling composition itself may need one or more preservatives to prevent microbial growth. More particularly, hair fixative resins dissolved or suspended in an aqueous composition, hereinafter called the "aqueous hair resin composition" can be inadvertently exposed to microbes such as bacteria, yeast, or molds. If the hair fixative resin supports microbial growth, preservatives will be needed in the aqueous hair resin composition to prevent this growth. The aqueous hair resin composition which needs a preservative may be for example the aqueous composition, such as an emulsion, in which the hair fixative resin is dissolved or suspended in before being added to the aqueous hair styling composition. The aqueous hair resin composition may also be the aqueous hair styling composition. The preservatives, however, added to the aqueous hair resin composition can destabilize the aqueous composition or may impart undesirable properties to the hair styling composition.
U.S. Pat. No. 4,196,190 to Gehman, hereinafter referred to as "Gehman" discloses an acrylic hair fixative resin containing from 10 to 30 weight percent of an alkyl acrylate, from 41 to 60 weight percent of methyl methacrylate, from 5 to 20 weight percent of hydroxyethyl methacrylate, and from 10 to 30 weight percent of methacrylic acid. The Gehman patent, although disclosing that water can be used in a hair styling composition containing the acrylic hair fixative resin, does not disclose or suggest the need for low VOC hair styling compositions. The Gehman patent also does not disclose or suggest how to obtain a low VOC hair styling composition, including methods of overcoming the problerns associated with low VOC hair styling compositions.
Some low VOC hair styling compositions have already been developed. For example, U.S. Pat. No. 5,176,898 to Goldberg, et al, hereinafter referred to as "Goldberg" discloses an aqueous hair spray formulation having less than 80 weight percent VOC. The aqueous hair spray formulation contains from 1 to 10 weight percent volatile silicone, preferably cyclomethicone or dimethicone copolyol, from 15 to 40 weight percent water/alcohol solution, from 5 to 60 weight percent propellant, from 1 to 10 weight percent water soluble hair fixative resin, and from 0.05 to 3.0 weight percent neutralizer/plasticizer. The dimethicone copolyol is a surfactant and makes the formulation easier to spray. However, the dimethicone copolyol, being a water soluble surfactant, has the undesirable effect of promoting beading when sprayed on the hair in a low VOC hair styling composition. Beading on the hair has the undesirable effects of leaving visible residue on the hair once dried and making the hair feel raspy when combed.
One problem addressed by the present invention is to provide certain plasticizing compounds which impart flexibility to hair fixative resins but do not adversely affect the tack, curl retention, or drying time of the hair fixative resin in a low VOC hair styling composition.
Another problem addressed by the present invention is to provide certain additives which reduce beading in a sprayable low VOC hair styling composition containing at least one soluble surface tension reducing compound and at least one hair fixative resin. The soluble surface tension reducing compound is any soluble compound which reduces the surface tension between the hair styling composition and the gaseous atmosphere above the hair styling composition. This definition includes for example, surfactants and plasticizers.
Another problem addressed by the present invention is to provide certain preservatives for acrylic hair fixative resins which are compatible with aqueous compositions containing the acrylic hair fixative resins.